Orion BT70 User manual

Brand: Orion

Model: BT70

Category: Binoculars

Type: User manual

Customer Support (800) 676-1343

E-mail: [email protected]

Corporate Offices (831) 763-7000

89 Hangar Way, Watsonville, CA 95076

INSTRUCTION MANUAL

Providing Exceptional Consumer Optical Products Since 1975

Orion

BT70 Binocular Telescope

#9547

IN 307 Rev. B 02/09

Figure 1. The Orion BT70 Binocular Telescope.

Handle

IP Knob (not visible)

Diopter scale

Lens shades (retracted)

Mounting plate (not visible)

Dovetail holder for handle

Eyepiece holders

The BT70 is a true binocular telescope, with optical quality

and features you’d expect of a fine astronomical instrument.

The included eyepieces provide 20x magnification, but

optional interchangeable eyepieces (available from Orion)

let you vary the magnification for deep-sky, solar system,

and terrestrial viewing - with 3D-like depth of field! The 90°

eyepiece viewing angle makes nighttime observing more

comfortable, as the binoculars don’t need to be positioned

above your head when looking upwards. The rugged body

construction and waterproof design ensure the BT70’s will

provide viewing enjoyment for years to come.

Please take the time to read this instruction sheet before

using your new binoculars.

Using a Tripod

When observing with large-aperture binoculars like the

Orion BT70s, a sturdy photo tripod or altazimuth mount is

required. This is because the weight and magnification of

the binoculars make it impossible to hold them steady with

your hands.

To attach the BT70 to a photo tripod, simply thread the

tripod’s 1⁄4"-20 mounting stud into the threaded hole in the

BT70’s mounting plate. The tripod must be able to support

approximately 10 lbs., otherwise it may not be stable

enough for the BT70.

To attach the BT70 to an altazimuth mount that utilizes a

dovetail holder, like the Orion VersaGo mount, an optional

dovetail L-bracket is needed. The L-bracket connects to the

BT70’s mounting plate, and has a dovetail bar that goes

directly into the mount’s dovetail holder. Contact Orion to

order this optional L-bracket.

Inserting the Eyepieces

Perhaps the most unique feature of the BT70 is its ability

to change eyepieces. The two supplied eyepieces provide

a magnification of 20x, but other magnifications can be

obtained by purchasing optional eyepiece sets from Orion.

To install the eyepieces, first remove the cover caps from

the binoculars and eyepieces. Then, simply insert the

eyepieces into the binoculars’ eyepiece holders (Figure

1). Push the eyepieces into the holders until they are fully

seated. To remove the eyepieces, just pull the eyepieces

out of their holders.

Extending the Lens Shades

Another nice feature of the BT70 is its extendable lens

shades (Figure 1). These increase image contrast by

preventing glare (unwanted stray light) from entering the

objective lenses of the binoculars. They also slow the

formation of dew on the objective lens exteriors. To use the

lens shades, grasp them with your fingers, and pull them

outwards.

You will need to retract the lens shades to fit the binoculars

into its case.

Adjusting the Distance Between Your Eyes

(Interpupillary Distance)

Adjusting the interpupillary (IP) distance of the BT70 is

incredibly easy. Simply turn the chrome IP knob located

between the eyepieces. Rotate the knob until the distance

between the eyepieces matches the distance between your

eyes. When properly adjusted, you should see a single,

round field of view when looking through the binoculars.

Make this adjustment before you attempt to focus the

binoculars.

Focusing

The BT70 binoculars utilize individual focus eyepieces.

This makes the binoculars mechanically more rugged than

similar center-focus models, and generally maintains optical

alignment better. For astronomical observation, individual

focus eyepieces are usually preferred.

Pick an object in the distance to view. At night, best focus

will be achieved by focusing on a bright star. Cover your

right eye (or cover the right objective lens of the binocular)

and focus the left eyepiece by rotating the rubber grip ring

on the eyepiece holder it until the image appears clearest.

Then cover your left eye (or cover the left objective lens

of the binocular) and focus the right eyepiece by rotating

the eyepiece holder until the image appears clearest. The

binoculars are now focused. If you want to view an object

at a different distance, re-focusing of both eyepieces is

required. Also, changing eyepieces may require some slight

refocusing.

For astronomical observation, all objects will always appear

focused at the infinity focus point. This means you only

need to focus the binoculars once per observing session.

This also means you can take note of the diopter scale

(Figure 1) setting for each eyepiece when focused on an

astronomical object, and return to those settings when

observing another night. You will find this to be a great

convenience!

Congratulations on your purchase of a pair of quality Orion binoculars. The BT70 Binocular Telescope provides the

large light grasp you need for astronomical observation, but unlike a telescope, allows you to use both eyes simultaneously

for viewing. This results in better image resolution, contrast, and brightness than a similar sized telescope can provide.

WARNING Never look directly at the Sun

through your binoculars without professionally

made solar filters, even for an instant, or

permanent eye damage could result. Young

children should use these binoculars on sunny

days only with adult supervision.

Since everyone’s eyes focus images slightly differently,

different observers will need to refocus the binoculars for

their own vision.

Fold-Down Eyeguards

BT70 binoculars feature fold-down eyeguards on the

eyepieces. The eyeguards are usually left in the up position

for use without eyeglasses, as this helps prevent glare

from entering between your eye and the eyepieces. To use

the binoculars with eyeglasses, you will need to fold the

eyeguards down in order to get your eyes close enough to

the eyepieces to see the entire field of view.

Waterproof Binoculars

The BT70 is nitrogen-purged and sealed to be waterproof

and internally fogproof. While it is impervious to rain, wind,

splashing, and humidity, do not immerse the binocular in

water under any circumstances. If the binocular becomes

wet with fresh water, merely blot it dry with a clean cloth and

clean the lens surfaces as outlined below. Saltwater should

be rinsed off completely and the binocular then blotted dry

and its lenses cleaned as outlined below. If the binocular

body becomes dirty, it can be cleaned with warm water and

a clean cloth. If extremely dirty, or oily, clean the body with

a dilute solution of warm water and mild soap on a cloth,

then rinse with clean water and blot dry. Do not clean lens

surfaces with soap and water!

Cleaning and Care of Binocular Lenses

The lens surfaces of Orion binoculars are coated with anti-

reflection multi-coatings that can be damaged with careless

handling. Avoid touching lens surfaces with fingers or any

coarse material. All optics, even if stored, should be cleaned

at least once a year or whenever they are dirty. The dust that

builds up on coatings promotes mold growth, which etches

glass and destroys coatings. Avoid over-cleaning; it can also

damage the coatings. Always use lens cleaning tissue and

fluid that are specifically designed for multicoated lenses. Do

not use fluids or tissues that are for eyeglasses or household

use. Never attempt to disassemble the binocular or eyepieces

in order to clean them; this can also void the warranty.

To clean the binocular (and eyepiece) lenses, first blow off

the lens with a blower bulb or gently wipe the lens with a lens

cleaning brush to remove the larger particles. Put a few drops

of lens cleaning fluid on a fresh piece of lens cleaning tissue

(never on the lens) and gently wipe the lens. Quickly wipe the

excess fluid with a new, dry piece of lens cleaning tissue. For

larger lenses, clean only a small area at a time, using a new

tissue each time. On excessively dirty lenses, wipe across the

lens using one stroke for each tissue, alternating wet and dry.

Always avoid excessive pressure or rubbing when wiping, as

wiping too hard can scratch the lens.

Storage and Transport

The BT70 binoculars come with a heavy-duty case for safe

storage and transport. We recommend always keeping the

binoculars in their case with the cover caps on when not in use.

The case has a lock on each latch for extra security. Use one of

the supplied keys to lock and unlock the latches. A removable

shoulder strap is also provided for ease of transport.

Avoid unnecessary shocks to the binocular, whether it is in its

case or not. Although the BT70 is designed to be mechanically

rugged, excessive impacts may cause the optics to become

misaligned. This is not covered by the warranty.

A metal carry handle is supplied with the BT70. This connects

to the dovetail holder on the binoculars, which is located just in

front of the eyepieces (Figure 1). Slide the handle’s base into

the dovetail holder, and secure it in place with the thumbscrew.

The handle comes in quite handy when attempting to mount

the BT70 onto a tripod. Before the BT70 can be placed into its

case, the handle must be removed.

Allow the optics to slowly adjust to cold weather by storing the

instrument (in its case) in a cold area, such as an unheated

garage or the trunk of a car, for a few hours before use. When

bringing the instrument back inside a warm house, open up

the case, remove the binoculars, remove the cover caps, and

let everything dry out. The binoculars should be stored in a

cool, dry place to prevent mold growth, which can damage the

optics. This is not covered by the warranty.

One-Year Limited Warranty

This Orion BT70 Binocular Telescope is warranted against defects in materials or workmanship for a

period of one year from the date of purchase. This warranty is for the benefit of the original retail pur-

chaser only. During this warranty period Orion Telescopes & Binoculars will repair or replace, at Orion’s

option, any warranted instrument that proves to be defective, provided it is returned postage paid to:

Orion Warranty Repair, 89 Hangar Way, Watsonville, CA 95076.

This warranty specifically does not cover abuse, modification, mishandling, self-repair, or normal wear

and tear (including mold growth). Binocular collimation (alignment of the optics) is specifically not

covered beyond the 30-day return period. Binoculars go out of collimation only if they are dropped or

bumped. Binocular collimation (and cleaning) are considered routine maintenance and should be done

every five years, or when necessary.

If the product is not registered, proof of purchase (such as a copy of the original invoice) is required. This

warranty gives you specific legal rights, and you may also have other rights, which vary from state to

state. For further warranty service information, contact: Customer Service Department, Orion Telescopes.

Objective lenses: 70mm clear aperture, air-spaced

achromatic doublets

Magnification: 20x eyepieces included, other

magnification eyepieces

available from Orion

Focusing: Individual focus eyepieces

Field of view: 3.2° for the included eyepieces

Eye relief: 16mm for the included

eyepieces

Close focus: 50 feet

Prisms: BAK-4, porro, provide 90°

viewing angle

Anti-reflection coatings: Fully multi-coated

Eyeguards: Fold-down, rubber

Body design: All metal construction, single

piece body design, waterproof

Interior: Glare threaded, baffled,

blackened

Lens shades: Retractable

Weight: 8 lbs. 15 oz.

Mounting provision: 1⁄4"-20 mounting plate

Carry handle: Included, metal, removable

Dust covers: Metal covers for objective

lenses, rubber caps for

eyepieces and eyepiece holders

Case: Custom foam-lined hard carry

case included, removable

shoulder strap, 2x lock latches

with keys

Specifications

Orion BT70 User manual

Brand: Orion

Model: BT70

Category: Binoculars

Type: User manual

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Orion BT70 User manual

Orion BT70 User manual

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